Improve App update experience

While updating app to developer portal there should be multiple sections to tell about the new version

  1. improvement - short summary of improvements
  2. Detailed summary - detail summary, video links, documentation which can help Freshdesk QA to understand about the new version and start QA without need to connect to the submitter.

Also, whenever a customer install app from the marketplace. The installed app should show currently installed version of the app and the version which is live in the marketplace